For any repaint it is important to consider the alpha channel. In FS2004 the alpha channel controls the reflectivity or transparency of a surface, in more recent simulators bump(normal) mapping has been introduced.

As this repaint was created for FS2004 we'll stick with the simple alpha channel.

An alpha channel is an extra channel to the Red, Green and Blue and is displayed in grey scale. If an alpha channel controls reflectivity, 100% black is 100% reflectivity (chrome) and 100% being nothing at all. If an alpha channel controls transparency, 100% black makes the surface completely see through and 100% white makes it solid.

Alot of paint kits will include an alpha channel within the "Channel" section. To view the channels go to Window - Channels.

Although useful to have included, an alpha channel is not easily editable so I prefer to make an alpha channel as an extra part of my paint scheme.

First lets place all of the folders and layers (if you have not already done so) in to one layer folder, name this layer folder something like "Paint Scheme".

Above this layer folder (outside of it) create a new layer folder and name it "alpha channel".

With the "alpha channel" layer folder selected, add a new layer and select the Paint Bucket Tool (G)

Select the active colour as white and fill the entire layer with this colour.

Repeat the process and fill another layer with black, make sure the black layer is above the white layer.

Leave the white layer at 100& opacity but set the black layer to around 3% opacity.

In order to produce the best effect and realisim we want there to be little to no reflectivity on our weathering. To do this, duplicate the weathering folder(s) for the psd.

You should now have something looking like this:

Right click the weather layer folder and select "Merge Group", this will now flatten the layer group and make it in to a single layer like the following:

We now want to make a selection from this layer, hold Crtl and click the thumbnail on the layer (or for eairlier versions of Photoshop, hold Crtl and click anwhere on the layer).

Don't be surprised if the following warning appears:

Now display the Channels by either going to Window - Channels or by clicking the Channels button on the Tool Bar

You may notice, as mentioned earlier, this paint kit actually already has a custom alpha channel named "Alpha 1".We're going to ignore this for the purpose of this tutorial but feel free to have a look at it.

Add a new channel by clicking the "create new channel" button at the bottom of the Channels box.

This should have added an entirely black channel.

With our weather selection and our new alpha channel selected, hit Delete on your keyboard a few times. This should start to remove the black, leaving a white version of our weathering.

Once you are happy that the alpha channel accurately displays our weathering press Crtl+D to cancel the selection.

Now we want to make a selection of our alpha channel, exactly how we made a selection from the weathering layer. Hold Crtl and click the thumbnail on the layer (or for eairlier versions of Photoshop, hold Crtl and click anwhere on the layer).

Return to our layers and add a new layer to our alpha channel folder.

Select the Paint Bucket Tool (G) and set the active colour as white.

Click anywhere on the sheet to fill the selection with white.

Press Crtl+D to cancel the selection

You should now have a white version of our weathering layer.

The reason for using this method is because Inverting the weathering layer, even once in grey scale, does not always work properly or give the best results. Making the selection from our weathering layer and simply filling another layer with white also does not always give the best results.

We now want to "chrome" some areas, mainly the leading edge of the tail.

Select the Magic Wand Tool (W) set the tolerance to around 5 and make sure "Sample All Layers" is selected.

Add a new layer and click on the leading edge of the tail. As we have set a very low tolerance it should only select pixels very close to the original colour and ultimately just select the leading edge. Instead of using the Magic Wand Tool (W) you could use the Polygonal Lasso Tool (L) to make the selection .

Select the Paint Bucket Tool (G) and fill the selection with 100% black.

Press Crtl+D to cancel the selection and set the layer's opacity to a very small amount, around 2%.

Save thecurrent file as the same file name as the fuselage bmp, simply add "_a" to the end of it for easy indentification, for example "posky757fuse1_t_a".

To deactive the alpha channel simply remove the layer group's visibility by clicking the eye next to the layer folder.

This has completed our fuselage alpha channel, repeat the process for the second fuseage psd.

We'll now have a look at the engines.

As you can see I've repeated the above process to acheive the following:

However by looking at the included alpha channel on the "Channels" tab we can see there are some useful bits we can use.

We can see the creator of this alpha channel as used 3 main shades of grey, to have the same level of reflectivity across all of the paint scheme we will however need to remove the medium shade of grey.

To do this we'll first transfer the entire alpha channel to our layer folder.

Select the Rectangular Marquee Tool (M) and make a selection covering the entire sheet.

Copy the selection by press Crtl+C.

Return to our layers and paste the copied channel in to our alpha channel layer folder, make sure it is at the top of the folder but below the weathering layer.

Select the Magic Wand Tool (W) and set the Tolerance to about 5 once again.

Click on an area of the medium shade of grey to make the selection.

Now press Delete on your keyboard to remove the medium shade of grey.

What should now happen is the grey from our black layer should show through, press Crtl+D to cancel the selection.

The alpha channel is now ready for saving.

For the posky757gear_t.psd we'll use a slightly different process.

In order to keep the same reflectivity we'll need to have the gear doors the same as the fuselage, in this 3% opacity from a 100% black layer.

First start by creating the alpha channel layer folder.

Display the channels and select the alpha channel named "alpha 1".

Select the Rectangular Marquee Tool (M) and make a selection covering the entire sheet.

Copy the selection by press Crtl+C.

Return to our layers and paste the copied channel in to our alpha channel layer folder, make sure it is at the top of the folder.

Now set the dragged over channel's opacity to a very small amount, around 5%.

You can now use the Rectangular Marquee Tool (M) to make a rough selection for the gear doors.

Use the Add to Selection and Subtract from selection buttons under the menu bar to refine your selection to just the gear doors.

Add a new layer to the alpha channel layer folder and select the Paint Bucket Tool (G), fill the selection with black.

With the same selection, select the alpha channel we brought over from the Channels.

Select the Paint Bucket Tool (G) and fill the selection with white.

Reset the alpha channel's opacity to white and our black layer to 3%

Your alpha channel is now ready for saving!

You can repeat the above processes for the wing textures and any remaining psds for our repaint.

When you come to repainting different aircraft you will notice that some paint kits do not come with alpha channels, or for whatever reason you need to create your own from scratch. To do this, simply start by adding the white layer as we did and then build up your black layers. This can be done by making a selection for an area you wish to apply reflectivity or chrome to, add a new layer and fill the area with 100% black. You can then experiment with the opacity of the layer to acheive the desired result. As you can only see the reflectivity and chrome properly within Flight Simulator it can become a timely process. However, as you create alpha channels you'll begin to recognise the best shade of grey to acheive the desired result.

Remember, if you want to see the paint scheme while creating the alpha channel simply lower the opacity of the white layer. This will allow the underlying paint scheme to show through. If you wish to partly see the entire paint scheme whilst creating the alpha channel you can lower the opacity of the layer folder. When you come to experiment with the layer opacities (and ultimately the shade of grey) you should reset the white layer or layer folder's opacity back to 100%.

We'll now move on to getting the paint scheme ready for it's final check and applying the alpha channel to the bmps for conversion.